Page 36 - Reservoir Formation Damage
P. 36

20    Reservoir Formation  Damage

                                       FRAYED  EOGESi





                       FLOWING  LOW-
                      POTASSWM SALT
                       SOLUTIONS
                                      PARTIALLY  ALTERED
                                                                  COMPLETELY  ALTERED

                                                         EFFECTS  OF  MICA  ALTERATION:
                                                         t.  PARTICLES  MADE  SMALLER
                   UNALTERED                            2.  EXPANDED STRUCTURE
                  MICA PARTICLE
                                                        3.  PARTICLES  MORE  MOBILE
                                                        4.  TRIGGERS INSTABILITY  IN  OTHER
                                                           MINERALS
                                                        5.  PLUGGED  PORES AND DECREASED
                                                           PERMEABILITY
                                        UNALTERED
                Figure  2-9.  Reed's  mechanism  of  mica  alteration  (after  Reed,  ©1977  SPE;
                reprinted  by  permission  of  the  Society  of  Petroleum  Engineers).





                                 Relative  size of  cations








                                             Piece
                                             broken  off
                                             the flake         Particles in
                                                               the  brine












                Figure  2-10.  Schematic  explanation  of  Reed's  (1977)  mechanism  for  particle
                generation  by  mica  alteration  during  exposure  to  low-potassium  salt  brine.
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